Autologous mixed lymphocyte reaction in multiple myeloma patients: effect of adherent mononuclear cells and T lymphocytes.

Autologous mixed lymphocyte reaction (AMLR) was measured in 12 patients with multiple myeloma. In ten patients depressed AMLR was found. Depletion of adherent monocytes caused enhancement of AMLR in those with a normal OKT4/OKT8 ratio. Only after monocyte depletion was a high correlation found between the AMLR values and the absolute number of OKT+4-T lymphocytes in the patients' peripheral blood. There was an inverse correlation between the suppressive effect of adherent monocytes on AMLR and the patients' serum levels of polyclonal IgG and IgM. Defects in both monocytes and OKT+4-T cells might have caused the low AMLR values and perhaps played a role in multiple myeloma immunodeficiency.